CN110337611B - Apparatus and method for exposing a photosensitive layer - Google Patents

Abstract

The invention relates to a method for exposing a photosensitive layer (9), the photosensitive layer (9) having an optical system (8), at least one light ray (6, 6') being generated in each case by at least one light source (7) and pixels (23) of an exposure pattern (24, 24', 24'', 24''') being illuminated by at least one micromirror device (1), the at least one micromirror device (1) having in each case a mirror intensity distribution (22, 22', 22''), characterized in that overlapping the mirror intensity distribution (22, 22', 22'') of adjacent micromirrors (3) for obtaining a pattern intensity distribution of the exposure pattern (24, 24', 24'', 24''') occurs as a sum of the mirror intensity distributions (22, 22', 22'') of each illuminated pixel (23) of the exposure pattern (24, 24', 24'', 24'''). Furthermore, the invention relates to an apparatus for exposing a photosensitive layer (9) using an optical system (8) having: at least one light source (7) for generating at least one light ray (6, 6'), at least one micromirror device (1) having a plurality of micromirrors (3), wherein each micromirror (3) is used for illuminating a pixel (23) of an exposure pattern (24, 24', 24'', 24''') having a mirror intensity distribution (22, 22', 22''), wherein the optical system (8) is constructed in such a way, so that the mirror intensity distribution (22, 22', 22'') of adjacent micromirrors (3) is overlapped to form a pattern intensity distribution of the exposure pattern (24, 24', 24'', 24''') as a sum of the mirror intensity distributions (22, 22', 22'') of the respective illuminated pixels (23) of the exposure pattern (24, 24', 24'', 24''').

Description

Apparatus and method for exposing a photosensitive layer

[ Field of technology ]

The invention relates to a method for exposing a photosensitive layer according to claim 1 and a corresponding device according to claim 8.

[ PRIOR ART ]

Digital Micromirror Devices (DMDs) have long been known in the prior art. These are optical components composed of a plurality of small mirrors that can be individually moved/aligned. The mirrors may be electronically controlled and oriented in a targeted manner. Thus, an optical system with a DMD may be used to deflect a broad range of light in a selective spatially resolved manner. In most cases, only two fully deflected positions are observed per mirror. A mirror allows the portion of light falling thereon to pass further through the optical system or reflect the portion of light such that the light is not relayed in the optical system. Then, we can interpret each mirror of the DMD as a digital optical switch.

DMDs of this type have been used in the prior art (mainly for projectors). DMDs are also increasingly used in industry such as, for example, 3D printing, 3D metrology, and unshielded photolithography.

In the prior art, only unshielded exposure units are known which have a single light source illuminating the DMD (and thus the surface to be exposed).

It is therefore an object of the present invention to overcome the disadvantages of the prior art and in particular to obtain an improved exposure result.

[ Invention ]

This object is achieved by the object of the patent claims which are mutually collocated and the inventive concepts disclosed hereinafter. Advantageous developments of the invention are specified in the auxiliary request item. All combinations of at least two of the features detailed in this specification, claims and/or drawings also fall within the scope of the invention. To the extent that values are within the limits mentioned, values which lie within the limits mentioned are also to be disclosed as limiting values and can be claimed in any desired combination.

In particular, the present invention indicates how an improved faster, high resolution exposure process can be performed and how an exposure can occur at different depths of focus simultaneously.

The core concept of the invention is to construct the micromirrors of a micromirror device of an optical system in such a way that the intensity distributions of the micromirrors are overlapped or constructed so that they can be overlapped with the intensity distributions of neighboring mirrors, respectively. Thus, each mirror intensity distribution is composed of a region corresponding to the pixel and a region surrounding the pixel. The mirror intensity distributions are at least predominantly (preferably entirely) defined by the optical components and the geometry of the micromirrors. The micromirrors are preferably rectangular, more preferably square. Round or triangular micromirrors are also contemplated. A DMD image is formed from pixels comprising overlapping pixels.

In particular, an exposure pattern is generated that is comprised of a plurality of mirror intensity profiles that at least partially overlap with a pattern intensity profile. Thus, the pattern intensity distribution is a sum of overlapping mirror intensity distributions. The exposure pattern preferably exposes a layer segment to be exposed on a substrate, wherein the pattern intensity distribution of the exposure pattern is preferably more uniform due to the overlay than an exposure pattern from the prior art without the overlay.

The mirror intensity distribution is preferably selected or adjusted or controlled such that 50% of the energy deflected by the respective mirror impinges on the corresponding pixel. An additional 50% of the energy deflected by the respective mirror is divided over the pixels surrounding the respective pixel. In a preferred embodiment according to the invention, the mirror intensity distribution is selected or adjusted or controlled such that more than 50% (more preferably more than 60%, more preferably more than 70%) of the energy deflected by the respective mirror impinges on the corresponding pixel. The remaining energy is divided over pixels surrounding the respective pixel.

In a different sub-preferred embodiment according to the invention the mirror intensity distribution is selected such that less than 50% of the energy deflected by the respective mirror impinges on the corresponding pixel.

In particular, the present invention describes an unshielded exposure apparatus or an unshielded exposure method. The exposure unit is described in several embodiments that can be combined with each other. In particular, these are optimization options that are independent of each other but combinable with each other.

The most important embodiment is to design the optical system in such a way that an overlap of individual pixels (pixels produced by the optical system) occurs (in particular, using overlap and/or interference). In particular, the effect of this is that the intensity distribution of the deflected light rays of adjacent micromirrors overlap.

In particular, a non-shielded exposure apparatus having at least two light sources is disclosed, wherein the light rays of the light sources overlap or combine or mix.

An apparatus for non-shielded exposure with integrated metrology is also contemplated in accordance with the present invention. A further embodiment relates to an unshielded exposure unit that allows simultaneous exposure of different focal planes or simultaneous exposure of different spectral portions of an image. According to a further alternative embodiment, an exposure unit having an anisotropic or distorting optical system for obtaining a higher resolution is disclosed.

A further, particularly independently disclosed embodiment relates to a "deflection scan (descan) method for increasing throughput and resolution. Here, by overlapping (in particular, sequential or sequential) the scanning exposure procedure by a second deflection in one or both directions, this will quasi-statically determine the exposure field with a finer positioning accuracy than the pixel size, thereby reducing both motion blur and edge position.

Furthermore, embodiments are disclosed in which the optical system produces an orthographic distortion plot (in particular, parallel to the surface of the layer to be exposed) of the original image between the DMD and the photosensitive layer to be exposed (the material to be exposed). In particular, positioning accuracy or overlay can be increased by optical distortion of the image. It will be appreciated that the positioning accuracy of an existing structure in certain cases means that the resolution of the structure to be written is increased by the distorted representation of the original image according to the invention.

Advantages of the invention

No masking is required so that the desired structure can be directly exposed into a photosensitive (photosensitive) layer. Due to the use of a plurality of light sources, a wider spectrum can be selected and the light output and thus the obtainable throughput is increased. By tilting the focal plane (compared to the surface of the layer to be exposed) or by individually selecting the wavelengths, different depths with full resolution can be exposed simultaneously or different planes can be selectively exposed.

According to the invention, the device has, in particular, an optical system with the following features:

At least one light source for generating at least one light,

At least one micromirror device having a plurality of micromirrors, wherein each micromirror is used to illuminate a pixel of an exposure pattern having a mirror intensity distribution,

Wherein the optical system is constructed in such a way that overlapping the mirror intensity distribution of adjacent micromirrors for forming a pattern intensity distribution of the exposure pattern occurs as a sum of the mirror intensity distributions of the illuminated pixels of the exposure pattern.

The invention describes a method and an apparatus for illuminating a photosensitive layer by means of a beam of light, in particular a laser, which is conducted through an optical system consisting of at least one micromirror device (DMD), preferably digital. Irradiation of the layer will cause a physical and/or chemical change in the layer.

In particular, embodiments according to the invention are conceivable as:

Full area

Continuous scanning

Step by step.

An unmasked exposure unit "unmasked" is understood to mean imaging by means of a dynamic optical patterning system instead of a static template (mask, reticle).

A full area unshielded exposure unit is understood to mean a device with a DMD which exposes the entire area to be written, wherein there is no significant relative displacement between the layer to be exposed and the optical system. Therefore, according to the prior art of the present invention, only a very small substrate can be exposed due to the limited size of the DMD.

A scanning type unshielded exposure unit is understood to mean a device or a method in which the exposure field is smaller than the area to be exposed, such that a relative displacement occurs between the optical system and the layer to be exposed to expose the entire exposure field. In particular, this relative displacement continues along a path. The path is preferably:

Tortuous of

In the column displaced to the next column and reset to the initial position when the object is reached,

Spiral-shaped, the shape of the spiral-shaped,

Circular shape, the shape of the circular shape,

Linear.

In particular, the paths mentioned can also be combined with one another. Thus, it is conceivable to first use a rotating path for the exposure, followed by a linear path that (in particular) leads through the center of the substrate or a plurality of initially independent write paths that are complementary to each other. The travel is preferably tortuous.

A step-wise unshielded exposure unit is understood to mean an apparatus in which the exposure field is smaller than the area to be exposed, a relative displacement between the optical system and the layer to be exposed occurs step by step and no exposure occurs between the individual steps. When the optical system and the layer to be exposed are positioned in a well defined position, the optical system exposes only the layer to be exposed. Thus, this embodiment involves exposing a plurality of sections of the layer to be exposed.

DMD principle

A DMD allows (preferably parallel and/or non-diffuse) a broad raw beam of light (particularly, a plurality of partial-to-target deflections). Therefore, a secondary optical exposure beam having a spatial structure can be generated without the assistance of a mask. In most cases, optics (particularly projection optics) are mounted upstream and/or downstream of the DMD, which optics can manipulate (particularly scale) the primary exposure light falling on the DMD and/or the secondary exposure light reflected by the DMD, and in particular, in the case of photolithography, can produce a reduction in the size of the DMD image. Therefore, the DMD image can be correspondingly reduced in size.

In particular, a structural resolution of the DMD die that can be obtained thereby is between 0.1 μm and 50 μm, preferably between 0.3 μm and 25 μm, more preferably between 1 μm and 10 μm.

Mainly, for embodiments in which the individual exposure fields are smaller than the substrate, it is important that a seamless succession of the structures to be produced occurs after a relative movement between the optical system and the layer to be exposed. In the case of stepwise, this occurs in two independent directions, and in most cases, in the case of continuous scanning, this occurs in only one direction.

Optical system

Embodiments in accordance with the present invention are comprised of at least one optical system that may have a plurality of optical components of different types. Although at least one of the optical components is a DMD, the use of a plurality of DMDs constitutes a further embodiment in accordance with the present invention. In particular, there is a single DMD in the optical system, preferably at least two DMDs, and more preferably at least four DMDs. The optical system itself may be used in one or more forms in parallel on a substrate within an apparatus. Parallel exposure of a plurality of substrates inside the apparatus is also envisaged according to the invention.

In addition, the following optical components may be included in the optical system:

Illumination optics

Specifically, coherent light source

■ Laser light source

Laser diode

Solid-state laser

Excimer laser

Specifically, incoherent laser source

■ In particular, a gas discharge lamp

Mercury lamp

■ LED

Partial coherent light source

O-coherence changing component

Deflection optics

○ DMD

Specifically, mirror

■ Cold reflector

■ Thermal mirror

Specifically, diffraction element

■ Prism

■ Beam splitter

Projection optics

Specifically, lens

■ Fresnel lens

■ Diffraction lens

Convex lens

Concave lens

Biconcave lens

Biconvex lens

Convex-concave lens

Meniscus lens

Cylindrical lens

Composite lens

Specifically, mirror

■ Columnar reflector

General light modifying optical assembly

The light sources may be used continuously or in a pulsed manner and, in particular, may additionally be modulated internally or externally.

In particular, the maximum possible relative speed between the optical system and the layer to be exposed is limited by the maximum driving frequency of the DMD (i.e., the frequency at which individual mirror assemblies of a DMD can actually be switched). The relative speed in a scanning system is also determined by the displacement and/or deflection optics and is in particular between 5 mm/s and 500 mm/s, preferably between 10 mm/s and 250 mm/s, more preferably between 15 mm/s and 200 mm/s, most preferably between 25 mm/s and 100 mm/s.

A further important aspect of an embodiment according to the present invention is that a feed rate is used that is higher than the feed rate defined by the pattern size and the scanning frequency. Due to the corresponding selection of a higher feed rate, the row compensated by the DMD exposure row later in time is omitted.

To avoid eliminating exposure in the scan direction, the exposure is interrupted and/or a local "" deflection scan "" mechanism is used, which will keep the exposure position constant for a short period of time. Hereinafter, the first possibility is considered first.

In particular, to compensate for a dose loss caused by a higher feed rate, the light output may be increased. This requires a large (in particular) instantaneous output of the light source, which often conflicts with increased costs or physical/technical limitations. To solve this problem, offset scanning and dynamic splitting of the output of a light source to a plurality of exposure units can be used as a more economical variable.

During the deflection scan, the relative movement of the image pixels with respect to the substrate is minimized and interrupted by a short time fast deflection (interlacing). Due to the small jumps, this deflection can be produced by means of a mechanical optical, electro-optical, magneto-optical or acousto-optical deflection or displacement unit.

During dynamic splitting of a light source, the output of the light source is dynamically suppressed (e.g., a tilted cavity laser, temperature limited semiconductor light source) and temporarily focused, or temporarily split between consumers by a distribution component such as, for example, a rotating polygon, electro-optic switch, or the like. The objective is to keep the long-term output constant all the time, except for increasing the short-term output during the duty cycle.

Integrated metrology optics

The device preferably has a measuring optics, in particular integrated in the optical system. In particular, a beam splitter is preferably used to couple light deflected by the layer to be exposed out of an optical path that is loaded on the DMD for exposure. The measurement optics have a plurality of important tasks that do not have to be performed all at once:

Alignment for aligning or reshaping the exposure field with structures present on the substrate,

Calibrating and checking the write head,

The write procedure is checked in situ,

Real-time correction (if dynamic changes in the relevant image substrate layers occur).

Alignment occurs with respect to an intentionally applied or existing structure that has been applied to the substrate or used as an alignment mark for the structure to be re-exposed. Thus, larger areas can be exposed according to the present invention because the optical system is always aligned and/or calibrated to the exposed structure.

A further important aspect according to an embodiment of the present invention is to calculate any substrate distortion caused by (in particular) initial process and/or thermal effects by comparing the current measured position of the alignment mark with the desired position and adapt the image to be written to this distortion. These may also be a higher order distortion.

In particular, alignment and/or real-time correction plays an important role in preventing joint artifacts (failure at the transitions between adjacent pixels and/or adjacent exposure patterns).

By capturing the structure of the exposure field (which may also be typical surface noise) during exposure and comparing it to one of the neighboring exposure structures, an offset of the substrate may be determined by correlation or the like. This offset is applied as a fault signal to the DMD image, whereby a compensation of degradation to the sub-pixel range is possible.

The capturing/measuring preferably takes place along the same optical path, which is also used for the exposure, so that a mechanical connection (in particular a mechanical fixation) can be achieved during capturing/measuring.

For capturing/measuring, the optical signal (light of at least one light source) is preferably coupled out of the surface by an optical component, preferably a half mirror or a prism, and absorbed by a corresponding detector. The detector (or an evaluation system connected thereto) may then monitor the surface of the layer to be structured as it is exposed and/or written upon. The detector is preferably a camera, more preferably a CCD or CMOS camera. The camera image may capture one or more portions, a larger area, or one or more smaller sections of the exposure field. The exposure may have its own light source and may occur in the same illumination wavelength range (preferred) or in a different illumination wavelength range.

In a specific extension embodiment, a measuring optic is also present on the bottom surface of the embodiment according to the invention, by means of which the alignment marks on the substrate holder or the bottom surface of the substrate can be detected. The bottom surface measurement principle of a substrate holder is similar to the embodiment disclosed in published document PCT/EP 2016/070289. Measuring alignment marks on the bottom surface makes it possible to produce structures that are aligned with respect to each other on both sides.

Intensity distribution function

In a first particularly preferred embodiment according to the invention, the imaging/secondary optics (for influencing (in particular, scaling) the secondary exposure light reflected by the DMD) are constructed in such a way that a clear imaging of the DMD mirror in the focal plane is not obtained, but rather a slightly unclear imaging of the neighboring pixels is deliberately obtained, which are also exposed. Thus, the optics can be constructed in a relatively inexpensive manner, and the quality of the resulting structure is still improved. The function of intensity distribution (intensity distribution) as a function of the diameter of the light ray may correspond to any desired mathematical function. The closed equation is used as one approximation of a more complex true distribution. In particular, it is mainly envisaged that:

gaussian distribution (Gaussian distribution),

A Lorentz distribution (Lorentzian distribution),

Kexidistribution (Cauchy distribution),

Convolution of different distribution functions.

In particular, the material of the photosensitive layer to be exposed has a defined (preferably non-linear) reaction behavior, which corresponds firstly to the accumulation Shen Jiliang of light and secondly to the output and thus to the exposure behavior. Thus, in the case of a local exposure gradient, an exposure edge is thus formed between the high and low doses, which can fluctuate within defined or definable boundaries. The present method uses this method and allows the position of this exposure margin to be controlled with an accuracy higher than the pixel size by overlapping a plurality of exposure fields (in particular, with respect to the individual micromirrors).

For a quasi-deterministic level, the exposure power is calculated in advance and decomposed into a plurality of exposure components (pixels in particular) and/or different exposure steps. The exposure steps, in particular, are temporally separated and/or of different lengths and they together result in a target exposure profile (pattern intensity profile) of a pattern level and/or a target exposure profile (substrate intensity profile) of a substrate level. Here, the relevant overlapping and/or incoherent overlapping of the individual distribution functions (mirror intensity distribution and/or pattern intensity distribution) and/or the image generation dynamics are preferably taken into account.

The result is a structuring of the exposure boundary, which is defined mainly as a sum of the exposure processes, but secondly, in the dynamic case, also taking into account the two-dimensional form and the three-dimensional shape of the material response to be or empirically determined. The term "overlap" and "interference" are explained in more detail below.

Multiple exposures of a respective partial region may also occur simultaneously and in a time delayed manner. So long as the variation of the exposed material is independent of exposure power and dependent only on flux (accumulated area dose), and no mechanical variation occurs (such as caused by heating or misalignment due to vibration or displacement), exposure field overlap (by simple addition) will result in the same result as a field exposed only to a light source.

In cases where non-linear relationships occur, these relationships may be compensated for by corresponding calculations or testing and subsequent adjustments to the partial exposure. In the case of random fluctuations, the overlap results in undesirable blurring or fluctuations that appear as image errors (e.g., blurring).

In the case of reproducible or precalculated overlap, edge roughness, run-out and other undesirable effects can be minimized and a clean stitching of the exposure field can be ensured. Even short-term exposure position fluctuations can be compensated for by the method according to the invention.

In the case of exposure to a plurality of light paths, interference effects occur in the optics if part of the radiation sources have exactly or almost identical temporal and spatial behavior due to their coherence. Here, the electromagnetic split wave field overlap is not merely averaged, but also creates constructive and destructive overlap in photosensitive surfaces and volumes that are slow relative to those in the THz range. These effects most often occur in the case of overlapping emissions from the same source, where the number of extensions within the coherence time is similar-thus, the dither behavior is dependent on each other. In the case of multiple exposures, photochemical interference effects may also occur, in which successive exposure steps react with each other. These have been considered in the control.

Preventing exposure failure at high speeds

In a second modified embodiment, an optimization of the data path is performed. One of the fundamental problems during the unmasked exposure step is that extremely expensive and complex calculations (e.g., rasterization) will be performed therein and extremely large amounts of data will be saved and transmitted. The data stored in the computer is synchronized with the relative motion between the optical system and the layer to be exposed or the DMD, or with the substrate. Structural data to be imaged in or on the layer to be exposed is saved on a computer. The structural data defines how the mirrors defining the DMD are switched in accordance with position to change the exposure light in such a way that the desired pattern falls on the layer to be exposed. In the case of a full area or step-by-step embodiment, the optical system (and thus the DMD) is always located at a defined (in particular, fixed) position. Thus, in this case, a dynamic correlation between position and structural data is not necessarily generated.

However, if a (preferred) scanning embodiment is used, a continuous exposure that varies according to position occurs, where new data is continuously provided to the DMD during the relative movement to control the micromirrors that vary according to position. Therefore, data for mirror control must be sent to the DMD quickly enough. Since the calculation mirror matrix is expensive, the various calculations are separated according to an advantageous embodiment. In particular, a distinction is made between time-critical calculations and non-time-critical calculations.

According to the present invention, time critical calculations are understood to mean all calculations that have to be performed quickly enough so that the data reaches the DMD before it changes its relative position with respect to the layer to be exposed.

In particular, the time critical calculations are:

specifically, image computation

DMD control

Specifically, sensor measurement and feedback calculation

Scanning and adjustment of the current writing position

Decompression of

Specifically, data for DMD and/or data to DMD

These computations require relatively high computation speeds, making a hardware computation preferable to a software computation. The hardware components that can be used for the computation are:

FPGA (field programmable gate array)

ASIC (application specific integrated circuit)

GPU (graphic processing unit)

Signal processor (DSP digital signal processor)

Non-time critical calculations are calculations that change only slightly in the exposure process device or are non-process critical, in particular:

converts the vector data into pixel data (rasterization),

Adjusting the size of the structure

Compensating for large area distortion

Inserting specific wafer data or specific die data (e.g., serial number)

Cutting data into strips for an individual write head

Rasterized vector data

Such computations are often very complex, involve a large data range (global adjustment in particular) in a computation step, and/or are not efficiently implementable by hardware in particular. These calculated channels

Implemented in at least one thread of the same computer or

Parallel execution in at least one thread of at least one other computer

Is reasonable. In this case, the threads may use GPU resources of the CPU and/or graphics adapter.

Communication between the computer and the DMD occurs via any desired interface, in particular:

Wire communication

○ USB，

The ethernet network is referred to as o,

○ DisplayPort。

A first improved embodiment is based on the fact that in the hardware for time critical calculations a memory is accessible which is large enough that at least two sections of the layer to be exposed (in particular, partial sections of the exposure path, preferably stripes, more preferably parallel stripes) can be saved and stored there. When a section to be exposed is written from the buffer/memory, a second section to be exposed is transferred from the computer to a unit for calculating a time critical task. When the same conditions are all present in the memory, the exposure process for a sector to be exposed is started for the first time. The second stripe is substantially fully loaded onto the memory before the first stripe has completed its exposure process. The following strip repeats this principle. Thereby effectively preventing the situation that there is no more data for time critical computation inside an exposure stripe and exposure failure occurs.

Correcting written data in real time

In a third modified embodiment, the mechanical failure is at least partially compensated for by the optical component. If the apparatus according to the invention exposes a continuous structure into the layer to be exposed in a scanning procedure, it is advantageous to set or provide a better positioning accuracy of the substrate holder than the overlay. All positional errors result from imperfect mechanical assembly, play, tolerances, an imperfect motor control, etc. Reducing errors by mechanical means is relatively complex. The design according to the invention allows for larger positional errors such as overlapping. In this case, measurement techniques are used to detect position errors and correspondingly, DMD images (in particular, in real-time) are shifted. According to one aspect of the invention, the position error is compensated such that the position error is less than the overlay specification at any point during the exposure process. In particular, the ratio between the overlay and uncorrected position errors is less than 1, preferably less than 10, more preferably less than 100.

According to the present invention, an error perpendicular to the relative movement or in the direction of the relative movement can be compensated.

In the case of errors perpendicular to the relative movement, a slightly narrower exposure stripe is used, but the DMD is designed to expose a wider exposure stripe. Thus, the left and right additional exposure areas act as a buffer. In case of a positional deviation of the substrate holder, the exposure stripes are transferred to the left or right in real time so that even if there is a positional error, the data is exposed at the correct position of the layer to be exposed.

Similarly compensating for errors in the direction of relative movement. If the substrate holder moves too slowly, the scroll rate (in particular the column period) is adjusted and the intensity is compensated by exposure control. If the substrate holder is moving too fast, the position of the exposure image can also be adjusted by the scroll speed (row period), however, it is only feasible to correct the dose by adjusting the exposure time when the exposure does not occur at maximum intensity.

The invention allows the use of an inexpensive mechanism and nevertheless achieves a high positioning accuracy.

Stripe overlapping (stitching)

In a fourth modified embodiment, the layer to be exposed is exposed in such a way that the calculated exposure sections (in particular, the strips) overlap. Preferably, the area at the edge of the strip is exposed twice. To prevent overexposure or underexposure, the intensity is changed or formed so that it can be changed in accordance with the position of the optical system (specifically, DMD). Preferably, the intensity profiles are then added together to obtain a constant or at least more uniform intensity profile. The overlapping of the strips can be considered as seams which should be exposed in such a way that they are ideally indistinguishable from a full area exposure. A more accurate description occurs in the descriptions of fig. 6 a-6 c. The reason why the stripe overlapping according to the present invention can be generated is not only to utilize the intensity drop at the edge of an exposed stripe, but also to use a dynamic illumination control in a targeted manner, which allows the intensity in the edge region of the exposed stripe to continue to drop. Thus, in particular, the present invention preferably allows control of the seam by means of target strength control.

Deflection scan

In a fifth modified embodiment, the exposure process occurs in such a way that in a first step the optical system or the DMD and the substrate (in particular, simultaneously, more preferably simultaneously) travel in the same direction and in this process step the light source is switched on as required. In a subsequent second process step, the optical system (or DMD) is displaced in a direction (preferably at a relatively high speed) opposite to the direction of movement of the substrate holder. In particular, no exposure occurs in this process step. Subsequent to the simultaneous movement, a partial return movement of the optical system is then carried out along the entire row (in particular for each other DMD row). A quasi-static exposure is produced by synchronous (in particular, collinear) relative movement between the optical system and the substrate. Thus, the flushing by the relatively moving exposure during scanning is reduced (preferably completely suppressed), and a better imaging can be obtained.

In a further improved embodiment, the exposure process occurs in such a way that in a first step a relative movement between the optical system and the layer to be exposed occurs in a first direction. In a second process step (particularly, running simultaneously), the optical system (or DMD) is displaced in a second direction (offset from the first direction) (particularly, disposed perpendicular to the first direction). Preferably, this displacement occurs in steps smaller than the imaging width of an individual pixel, thus producing a relatively fine imaging dot positioning pattern. Simultaneous movement subsequent to lateral movement of the optical system allows for increased positioning accuracy or overlay. Due to the synchronous (in particular, non-collinear) relative displacement between the optical system and the substrate, the elimination of exposure by relative movement during scanning is reduced (preferably completely suppressed) and a better imaging can be obtained.

In an embodiment according to the invention, all components (in particular optical components) for generating an image are adjusted by means of piezoelectric components. In particular, electro-optical/mechanical optical components may be used. The image is displaced in the x and/or y and/or z direction by the control. A plurality of components may also be used which may perform translational and/or rotational movements of the image, in particular. The image may be tracked at a speed corresponding to the scan speed.

Exposing different structures on different focal planes simultaneously

In a sixth modified and preferred embodiment, the focal plane is tilted with respect to the layer to be exposed. During an exposure, the position of the focal plane and the depth of focus are important to the quality of the imaged structure. The focal plane may be tilted in several ways.

In a first development of the sixth embodiment, the focal plane is changed by mechanically tilting the entire DMD. This embodiment is the most preferred.

In a second preferred development of the sixth embodiment, the focal plane is influenced by targeted modification of the optical components connected upstream and/or downstream of the DMD. The tilt of the focal plane is influenced by means of the optical component. Preferably, the focal plane is statically set at a time and different areas of the DMD are used to expose different depths of the layer to be exposed.

In a third development of the sixth embodiment according to the invention, a plurality of (in particular, continuous) focal planes are generated in (or through) the layer to be exposed using a plurality of light sources of different wavelengths and/or light sources having a broadband wavelength spectrum.

In this embodiment, the layer to be exposed is preferably formed of a material (in particular, a polymer) that is sensitive to corresponding radiation across the entire wavelength range.

Dynamic exposure control for gray scale lithography

In a seventh modified embodiment, the intensity at each location is controlled in a targeted manner by one of the following methods. Thus, overexposure and/or underexposure may be compensated. In addition, a low quality structure can be improved and an exposure gradient can be generated. By targeted control of intensity at various locations, it is possible to generate (in particular)

3D structure

Gray scale lithography and/or

Optical proximity correction.

A very important aspect of using DMDs is that the photon intensity impinging on the layer to be exposed is distributed in a spatially correct manner. No light source can be said to be an ideal spotlight, and therefore no light source has a uniform intensity distribution. Therefore, the light irradiated onto the DMD is also non-uniform. Preferably, the light is homogenized by optical components in the optical system before it impinges on the DMD.

According to the invention, not only the uniformity of the light source is modified, but also the DMD (in particular its micromirrors) is adjusted for a light beam deflected onto the layer to be exposed with the correct intensity distribution. There are a number of advantageous measures for correctly controlling a complex spatial intensity distribution.

In particular, the output of the light source is between 0.01 and 1000 watts, preferably between 0.1 and 500 watts, more preferably between 1 and 250 watts, most preferably between 5 and 100 watts, most preferably between 9 and 13 watts.

The intensities are specified in W/m ². The intensity can be calculated easily from the radiation concentrated onto a unit area by the optical component. Preferably, the intensity of the light source can be adjusted extremely precisely. The intensity is varied by varying the output of the light source, by the duration of the exposure, and/or by optical components in the optical system. Thus, according to the present invention, light of different intensities can be radiated onto the DMD for a well-defined period of time. By means of a corresponding mirror control, individual points of the layer to be exposed can thus be irradiated with defined intensities. The surrounding points of the layer to be exposed may be illuminated with an intensity different from that.

According to the invention, there is the possibility of exposing the layer to be exposed resolved in a targeted punctiform manner (in particular in relation to the individual pixels). By means of a relative movement between the optical system and the layer to be exposed, the optical system can travel to each position several times, so that each pixel to be exposed can be exposed several times. Multiple exposures can be controlled in such a way that a most uniform exposure degraded to the pixel level is obtained by a measurement system and target analysis of the quality of the surface.

Thus, on the one hand, as long as a uniform pixel exposure is desired, the intensity unevenness from an original light can be compensated, and on the other hand, exposure doses which differ in a manner based on address can be introduced into the layer to be exposed.

Furthermore, the exposure sections (in particular, the strips) to be exposed can be overlapped by means of the mentioned embodiments according to the invention. Individual pixels are exposed multiple times by an overlap. From the number of exposures of each pixel, the desired intensity portion of each respective exposure process (exposing the pixel in accordance with that intensity portion) can be calculated.

If the imaging has a structure with an intensity gradient, then (in particular) it is determined according to the invention how often a pixel should be exposed to the intensity, so that in the case of n repetitions each pixel is already loaded with the determined absolute intensity at the end of the exposure process.

Anisotropic and/or distorted imaging optics for improving overlay error and/or motion blur

In a further eighth embodiment according to the invention, the horizontal and/or vertical exposure pattern grid lines (in particular, not quadratic) of the exposure pattern are imaged differently by means of optical imaging, so that a different exposure pattern resolution is set in the vertical and horizontal directions. The calculation/control of the exposure is compensated by the deviation.

In a further embodiment, the imaging axis or exposure pattern grid lines are not orthogonally arranged, but are arranged in an oblique extension. Using such a projection (particularly affine distortion) (particularly a cut) would allow for a simple calculation of the linear guide under precise layout (sub-pixel level accuracy) of the illumination points below the radiation position and grating resolution to obtain precise information of the exposure edge.

In a further embodiment according to the invention, the horizontal and/or vertical exposure pattern grid lines of the exposure pattern in the vertical and/or horizontal direction are not realized equidistantly.

Different exposure patterns may be generated from a uniform isotropic image of the DMD by optical components connected upstream and/or downstream of the DMD and/or the exposure patterns may be a direct result of an anisotropically and/or unevenly structured DMD.

In addition, several possibilities are shown to generate a corresponding projection (in particular, a shearing of the exposure pattern) according to the invention.

In a first possible embodiment according to the invention, at least one lenticular lens having a cylindrical axis is used as imaging optics to influence a change in the exposure pattern. In particular, just two lenticular lenses are used. The cylindrical axis of the lenticular lens is preferably parallel to the surface to be exposed. To obtain a shear according to the invention, an angle of less than 90 ° (preferably less than 70 °, more preferably less than 50 °, most preferably less than 20 °) is provided between the two cylindrical axes. However, the optimum angle in the owner is due to the shear angle to be produced.

In a further embodiment according to the invention, the optical system consists of only a single so-called compound lens. A compound lens is understood to mean a lens whose surface is ground in such a way that the optical properties are identical to those obtained by combining the two lenses.

Thus, both regular and irregular irradiation of the substrate may result in the embodiments specified above. In the specific case where an exposure repetition rate is regular but not exactly matches the travel speed as a whole, an exposure structure is additionally activated just for the current writing position. Accordingly, non-integral displacement of the subpixel layout will affect the direction of travel, which will result in an improved layout accuracy and improved edge roughness.

A combination of the above described sets and/or time shifts will produce a sub-pixel resolution in all directions and will reduce sensitivity to errors (as compared to faults in individual exposure components). It is necessary to know the distortions caused by imaging errors and/or artificially caused to characterize the correct exposure dose distribution. The linear distortion image or rotated image has the advantages of simpler computation and simpler light source control.

Motion blur reduction

In a further ninth embodiment according to the present invention, the relative speed and/or movement between the optical system and the layer to be exposed is varied in such a way that a plurality of pixels overlap within a pixel size. The overlay may be interpreted as a long-term exposure of a moving object. Thus, one of the pixels is eliminated in the relative movement direction. The pixel size in the relative movement direction may be set in a targeted manner due to determining when to write or not write one of the pixels. For clarity, see fig. 8 a-8 b or corresponding descriptions of these figures.

In other words, two exposure patterns sequentially illuminated one after the other are shifted or shifted to have a relative shift between the micromirror device and the pixel photosensitive layer that is smaller than a pixel width (preferably smaller than half a pixel width, more preferably smaller than a quarter of a pixel width).

If the reduction or expansion of the optics in the scanning direction is substantially smaller than in the direction orthogonal to the scanning direction, the motion blur effect due to the limited exposure time can be partially compensated. This makes it possible to obtain an isotropic image. Compression in the direction of movement does not reduce the motion blur itself, but only reduces the total extent of the exposure point in the direction of travel.

The mentioned owners of the embodiments and processes according to the invention may be combined with each other as desired, but they are described separately. Whenever a method feature is described, it should also be considered to be disclosed as a device feature and vice versa.

[ Brief description of the drawings ]

Further advantages, features and details of the invention will be obtained from the following description of preferred exemplary embodiments and on the basis of the drawings. In the drawings:

figure 1 shows a first embodiment of the device according to the invention,

Figure 2 shows a second embodiment of the device according to the invention,

Figure 3 shows a third embodiment of the device according to the invention,

Fig. 4a shows a schematic depiction (not to true scale) of a DMD (micromirror device) having an enlarged partial section containing micromirrors in a first position,

Fig. 4b shows a schematic depiction (not to true scale) of a DMD (micromirror device) having an enlarged partial section containing micromirrors in a second position,

Figure 5a shows a schematic drawing (not to true scale) of a plan view of a first exposure section of a layer to be exposed,

Fig. 5b shows a schematic drawing (which is not true to scale) of a plan view of a second exposure section of a layer to be exposed, which is slightly offset with respect to the first exposure section,

Figure 6a shows a schematic drawing (not to true scale) of a plan view of a substrate having a first exposure section,

Figure 6b shows a schematic drawing (which is not to true scale) of a plan view of a substrate having a second exposure section,

Figure 6c shows a schematic depiction (not to true scale) of a plan view of a substrate having overlapping first and second exposure sections,

Figure 7a shows a schematic drawing (not to true scale) of a further embodiment of the device according to the invention,

Figure 7b shows a schematic drawing (not to true scale) of a further embodiment of the device according to the invention,

Figure 7c shows a schematic drawing (not to true scale) of a further embodiment of the device according to the invention,

Figure 8a shows a schematic representation (not to true scale) of a plan view of a further exposed section of a layer to be exposed according to a first embodiment of the method of the invention,

Figure 8b shows a schematic representation (not to true scale) of a plan view of a further exposed section of a layer to be exposed according to a second embodiment of the method of the invention,

Figure 9a shows a schematic depiction (not to true scale) of a first embodiment of an exposure pattern according to the invention,

Figure 9b shows a schematic depiction (not to true scale) of a first embodiment of an exposure pattern according to the invention,

Figure 10 shows a schematic diagram of an intensity distribution of one of two adjacent pixels having three different intensities,

FIG. 11 shows a schematic diagram of an exposure pattern having a plurality of exposure pixels, an

FIG. 12 shows a schematic diagram of an exposure pattern distorted by optical components.

In the drawings, the same reference numerals are used to designate the same elements or elements having the same functions.

[ Embodiment ]

Fig. 1 shows a first embodiment consisting of an optical system 8 with at least one light source 7 and at least one DMD 1 (micromirror device), a substrate holder 11. The substrate holder 11 can be moved relative to a coordinate system K3.

A substrate 10, on which a photosensitive layer 9 made of a material that can be exposed, is located, is fixed to the substrate holder 11 using fixing members 13, the photosensitive layer 9 being exposed by the apparatus.

The origin of coordinates of the coordinate system K2 of a sample-fixing (i.e. fixing to the substrate 10 or the layer 9 to be exposed) is preferably arranged in the center of the surface 9o of the layer 9.

Light rays 6 (primary rays) emitted by the light source 7 and passing through a plurality of optical components (not shown) on their way to the DMD 1 are converted by the DMD 1 into a structured light ray 6' (secondary rays). Which may pass through a plurality of optical elements (not shown) on its way to layer 9.

A detector 19 (in particular, a camera, more preferably a CCD or CMOS camera) captures and/or measures the surface 9o of the layer 9 to be exposed by means of a semi-transparent mirror 14'. The measured structure is preferably used for calibration of the direct control method and/or device. The depiction of such measurement components may be omitted from the further description of the drawings and the drawings for clarity. However, the measuring means according to the invention may be used in the embodiments according to the invention mentioned.

Fig. 2 shows a second embodiment, in which the optical system 8 is equipped with two light sources 7, 7'. The two light sources 7, 7' emit light rays 6. One of the light rays 6 is diverted by a mirror 14 onto a beam splitter 14 'and combined with the light rays 6 of the second light source 7' by means of the same reflector.

The combined light rays 6 are directed onto the DMD 1 and converted by the same DMD into a structured light ray 6', which in turn may pass through a plurality of optical components (not shown) on the way to the layer 9.

An independent aspect according to the invention is mainly that the radiation intensity, wavelength, associated length and, if appropriate, other properties or parameters of the two light sources 7 may be different, so that a plurality of different optical parameters may be used for generating a laser beam 6.

According to the invention, in particular more than 2, in particular more than 5, more preferably more than 10, most preferably more than 20 light sources 7, 7' may be used. Each light source may preferably be an LED field or LD (laser diode) field.

Fig. 3 shows a third embodiment consisting of an optical system 8 with at least one light source 7 and two DMDs 1.

A light ray 6 is emitted by the light source 7 and split by means of a beam splitter 14'. A first split light ray 6.1 is modified by a first DMD 1 to form a first modified light ray 6.1'. The layer 9 is exposed using the first modified light ray 6.1'. The second split light ray 6.2 is diverted by a mirror 14 onto a second DMD 1 and is diverted as a second modified light ray 6.2' onto the layer 9. The second modifying light 6.2 'is preferably used instead of the first modifying light 6.1' to expose a different location of the layer 9 to be exposed. The owners of the mentioned light rays may pass through a plurality of optical components (not shown).

An independent aspect according to the invention is that the user has at least two DMDs 1 by means of which the layer 9 can be exposed at two different positions simultaneously, wherein preferably a single (in particular) combined light is used for loading the DMDs. In particular, this results in one of the exposure sections (in particular, one exposure strip) spreading and thus in one of the throughput increases.

Fig. 4a shows a DMD 1 with a mirror 2. An enlarged drawing of a part of the mirror surface 2 shows a plurality of (16) mirrors 3 of the plurality of mirrors 3. The mirrors are arranged in a non-tilted alignment, which is designated as the initial position. A coordinate system K1 is assigned to DMD 1. The Z-axis of K1 (i.e., K1Z) is perpendicular to mirror 2, and the x and y coordinates are parallel to mirror edges 2kx and 2ky of mirror 2 and define a mirror plane.

Fig. 4b shows the same DMD 1, wherein one of the mirrors 3 is arranged in an inclined position or in a position rotated about the x-axis. Thus, the portion of the light ray 6 irradiated onto the inclined mirror 3 is reflected in a direction different from the reflection direction of the portion of the light ray 6 reflected by the non-inclined mirror 3.

Fig. 5a shows a schematic view of the mirror 2, in each case the mirror 2 having a central (in particular stripe-shaped) writing area 4 and two (preferably parallel) buffer areas 5 at the edges, which are adjacent to the writing area 4.

Unlike mirror 3, pixels 23 of an exposure pattern 24 reflected by mirror 2 are shown, which correspond to the formation structures 12 (which may be modified by the optical components between DMD 1 and layer 9 to be exposed) at the k2y=12 position on layer 9 to be exposed.

According to an advantageous embodiment of the invention, only the mirror 3 arranged in the writing area 4 is used for exposure, so that the buffer area 5 forms a writing buffer, as explained below. The centerline D extends through a fixed center point 0 of the K2x axis of the sample coordinate system.

Fig. 5b shows the same DMD 1 after one of the relative movements of 0.5 a.u. in the K2y direction. DMD 1 is therefore located at a position k2y=12.5a.u. It can also be seen that a relative movement of about 2 a.u. has occurred in the K2x direction. This relative movement is desirable and results from, for example, a failure in the installation. It is clear how to displace the structure 12 to the left relative to the DMD coordinate system K1 to properly expose the structure in the coordinate system K2 y. Therefore, a write buffer is used.

Thus, the target programming of the DMD will allow for correction of mechanical faults. Thus, the substrate holder 9 does not move the substrate 10 (and thus the layer 9) in the K2y direction along a complete straight line, but rather there is a slight displacement towards one of the K2x during movement in the K2y direction.

According to the invention (a separate aspect of the invention), the mechanism of the substrate holder 9 is preferably not used to correct the fault, but rather the writing area 4 and the buffer area 5 are programmed/electrically controlled in such a way as to displace the structure 12 to be exposed correspondingly (here in the negative K1x direction). Thus, the electronics and/or mechanisms of the DMD 1 compensate for write errors (here, mechanical failure of the substrate holder 11).

Figure 6a shows a plan view of a layer 9 exposed along a first stripe 15. The strips 15 correspond to the areas of the layer 9 that are exposed by the writing area 4 of the DMD 1 after the DMD 1 has been moved in the K2y direction relative to the exposed layer 9.

In a region between the intensity-varied regions 16l, 16r of the strip 15, the illuminated pixels 23 are illuminated with an intensity which is as uniform as possible.

In contrast, the illuminated pixels 23 in the intensity-varying regions 16l, 16r are controlled in such a way that the intensity (in particular, the duration) of the reflected light 6' reflected from the writing region 4 in the direction of the edge of the DMD 1 decreases (preferably in direct proportion to the distance from the writing region 4). The marks correspond to (from which the intensity profile can be read) the pattern intensity distribution (intensity/position) according to one of the position variations. The intensity used for exposing the layer 9 thus has a maximum in the region of the strip 15 and normally drops (preferably smoothly and/or linearly) laterally to zero.

Fig. 6b shows a drawing similar to fig. 7a, in particular with respect to a second strip 15' exposed next to the first strip 15. Which is displaced to the right relative to the first strip 15 such that the right-hand intensity-varying region 16r of fig. 6a overlaps (preferably overlaps) the left-hand intensity-varying region 16l' of fig. 7 b. The pixels 23 are connected in the right-hand intensity distribution area 16r in a precisely distributed manner as in the left-hand intensity variation area 16l', wherein the intensities of the corresponding pixels 23 are summed to obtain a pixel intensity corresponding to the intensity in the strip 15.

Fig. 6c shows a plan view in which the intensity variation region 16r of the first strip 15 is superimposed with the intensity variation region 16l 'of the second strip 15' such that a constant intensity distribution is obtained. Thus, exposure occurs uniformly as the intensity of the first strip 15 is summed with the intensity of the second strip 15'.

Fig. 7a shows an amplifying section according to an embodiment of the invention, which has an optical path of a DMD 1, primary light rays 6 and secondary light rays 6' and the layer 9 to be exposed. Here, the primary light rays 6 and the secondary light rays are symbolized by only the optical paths 6, 6', and are preferably large to illuminate the entire DMD 1. The second light ray 6' is perpendicular to the layer 9 to be exposed. In particular, focal plane 17 is parallel to surface 9o (preferably on surface 9 o). A depth of field range 18 represents the depth within which a clear imaging of pixel 23 may occur.

Fig. 7b shows an enlarged section according to a preferred embodiment of the invention, which is varied compared to the embodiment according to fig. 7 a. The second light ray 6' is reflected at an angle α to the layer 9 to be exposed. Thus, the focal plane 17 intersects the layer 9 to be exposed at an angle α. On the left side, it is located outside the layer 9 to be exposed, and on the right side, it is located in the layer 9 to be exposed. The depth of field range 18 thus penetrates deeper into layer 9 on the right and can thus be used to create a clear structure of three-dimensional structure in the recess without moving focal plane 17 in the K2z direction by moving DMD 1.

In particular, the act of displacing the DMD 1 in the K2z direction in order to more clearly image deeper located structures may be avoided by tilting the DMD 1. Thus, the dynamic displacement of the exposure area on the DMD 1 allows for a clear exposure of a target at the corresponding depth. An important advantage compared to multiple exposures is that structures can be produced with high accuracy without mechanical failure in all spatial directions.

Fig. 7c shows an enlarged section according to a preferred embodiment of the invention, which is varied compared to the embodiments according to fig. 7a and/or fig. 7 b. The secondary light rays 6' are deflected in such a way by means of an optical component (not shown) located between the DMD 1 and the layer 9 to be exposed that the focal plane 17 is inclined at an angle α with respect to the substrate surface 9 o.

Fig. 8a shows a plan view of a section of a part of the layer 9 to be exposed. A pixel 23 (the smallest unit of an exposure pattern 24) is illuminated along a length l by the DMD 1, because a relative movement has occurred between the DMD 1 (not shown) and the layer 9 to be exposed, and an exposure of the layer 9 in the region of width b takes place during the entire travel along the length l by illuminating the pixel 23. The exposed area corresponds to a pixel 23, wherein the intensity of the exposure is controlled by the illumination intensity. In the case of overlap, the intensities in the overlap region are summed.

Exposure occurs from K2y position 0 up to K2y position 3. Elimination in the direction of relative movement occurs because a plurality of exposures occur in the range from about-2 to about 5 during the relative movement. The intensity profiles of the pixels 23 overlap and produce a stronger intensity increase along the path 1.

Fig. 8b shows an alternative embodiment of fig. 8a, wherein a smaller length l' is produced, differing from fig. 8a in that the corresponding mirror 3 (not shown in the figure) of the DMD 1 is exposed first from the K2y position 1 and the exposure has ended at the K2y position 2. Thus, the resolution in the K2y direction can be increased by means of target control of the mirror 3 (in particular when the latter is switched on later or switched off earlier). Therefore, in practical cases, the start of exposure of the pixel 23 is delayed by 33.33% and ended by 33.33%. Since each light ray has an intensity distribution that deviates from a step-by-step shape, the pixel 23 cannot be exposed secondarily. The exposure patterns 24, 24', 24 ", 24'" are depicted as reference lines, which we can envisage being located above the layer 9 to be exposed. The patterns preferably correspond to the size of the pixels 23.

Fig. 9a shows a first exposure pattern 24 which is sub-optimal according to the invention and which has exposure pattern grid lines 27 equally spaced in two mutually orthogonal directions K2x, K2 y. Thus, the exposure pattern 24 is isotropic and uniform in both directions of K2x and K2 y.

Fig. 9b shows a second preferred exposure pattern 24' according to the invention having a separate spacing for each direction (in particular, with respect to that direction) that is equidistant between the exposure pattern grid lines 27. Thus, the exposure pattern 24' is anisotropic but uniform in each of the directions K2x and K2 y.

It is also contemplated that the exposure occurs at the intersections 25 of the exposure pattern grid lines and/or at portions of the exposure pattern areas 26 and not within the individual pattern areas.

In particular, the different exposure patterns 24, 24', 24 ", 24'" may be generated/modified by means of optical components (not shown) mounted upstream and/or downstream of the DMD 1 (not shown). DMD 1 (not shown) will preferably be isotropic and uniform, with (particularly, downstream) optical components (not shown) configured to affect an anisotropic and/or uniform imaging of the DMD.

Fig. 10 shows a schematic cross-sectional illustration of two mirrors 3 and mirror intensity distributions 22, 22' (in particular gaussian distributions) and pixels 23, 23' resulting from these intensity distributions 22, 22', which are realized by means of three different parameter sets and/or constructional variations of the mirrors 3. It can be seen that the intensity distribution with the gradually increasing parameters of the characterizing distribution function, in particular the full width at half maximum ((FWHM) FWHM, FWHM ')), is even more highly overlapping, so that two pixels 23, 23' adjacent to each other are more strongly eliminated. In the case of the highest overlapping pixels 23', the result is a very uniform exposure pattern.

Fig. 11 shows a schematic plan view (not to true scale) of a plurality of pixels 23 on a 5 x 5 exposure pattern 24. A pattern 28 is visible which is illuminated by the target connection of the corresponding mirror 3. The mirror intensity distribution of the mirrors 3 is so clear that the intensity maxima are clearly visible and the intensity drops and is so pronounced that the intensity distribution per mirror 3 (not shown in the figures) is extremely highly limited by the assigned partial exposure pattern areas 26. Specifically, in a preferred embodiment according to the present invention, the mirror intensity distribution overlaps with the outer part of the partially exposed pattern region 26, as is the case with the pixel 23' according to fig. 10.

Fig. 12 shows a schematic plan view (not to true scale) of an exposure pattern 24' distorted by the optical components of the optical system 8 (in particular). Part of the light reflected by the mirror 3 of the DMD 1 is reflected orthogonally by means of optical components onto the layer 9 to be exposed, but a distortion occurs (preferably only) in the K2x-K2y plane. An exposure pattern 24' can be produced by this method according to the invention, which according to the invention will result in an increase in the overlap. In this embodiment, DMD 1 is preferably not tilted, but rather the original image of DMD 1 is affine distorted to affect the tilt of exposure pattern 24'.

[ Symbolic description ]

1 DMD

2. Mirror surface

2Kx, 2ky mirror edge

3. 3' Mirror

4. Writing area

5. Buffer area

6. Light ray

6' Modified/structured light

6.1' First modified light ray

6.2' Second modified light ray

7. 7' Light source

8. Optical system

9. Layer(s)

10. Substrate board

11. Substrate holder

12. 12', 12' ' Structure

13. Fixing member

14. Reflecting mirror

14' Beam splitter

14'' Semitransparent mirror

15. 15', 15″ Strip

16L, 16r, 16l ', 16r', 16r″ intensity variation regions

17. Focal plane

18. Depth of field range

19. Detector device

20. Dot pattern

22. 22', 22' ' Mirror intensity distribution

23. 23' Pixel

24. 24', 24' '' Exposure pattern

25. Grid line crossing point of exposure pattern

26. Partially exposed pattern area

27. Grid line of exposure pattern

28. Pattern and method for producing the same

L, l' length

B width

D center line

V vertical dot pattern spacing

H horizontal dot pattern spacing

Radius of r exposure point

P mirror center spacing

Claims (14)

1. A method for exposing a photosensitive layer of a substrate using an optical system and a substrate holder, the substrate being fixed on the substrate holder, the optical system comprising one or more light sources and one or more micromirror devices, the one or more micromirror devices each having a plurality of micromirrors, the plurality of micromirrors each having a mirror intensity distribution with: the areas respectively corresponding to pixels of an exposure pattern to be exposed on a partial area of the photosensitive layer, wherein a measuring optic is integrated in the optical system, the method comprising:

a first step of simultaneously and synchronously moving the one or more micromirror devices and the substrate in a first direction;

During the first step, respectively emitting one or more light rays from the one or more light sources for reflection by the micromirrors to expose pixels of the exposure pattern according to areas of the mirror intensity distribution respectively corresponding to the pixels of the exposure pattern, respectively, wherein the one or more light rays are coupled using a beam splitter of the measuring optics, wherein adjacent mirror intensity distributions of the micromirrors overlap as a sum of the mirror intensity distributions of each illuminated pixel of the exposure pattern to give a pattern intensity distribution of the exposure pattern, wherein the beam splitter couples light deflected by a layer to be exposed out of an optical path that is loaded on the one or more micromirror devices for exposure; and

A second step of moving the one or more micromirror devices in a second direction opposite or perpendicular to the first direction after emitting the one or more light rays, wherein when the second direction is perpendicular to the first direction, the displacement of the one or more micromirror devices occurs in a step less than an imaging width of an individual pixel.

2. The method of claim 1, wherein the pixels are larger than individual patterns of the exposure pattern.

3. The method of claim 2, wherein the pixels are generated based on the geometry of the micromirrors.

4. The method of claim 1, wherein the exposure pattern is one of two or more exposure patterns,

Wherein pixels of at least two exposure patterns of the two or more exposure patterns are exposed, an

Wherein the pattern intensity distributions of the at least two exposure patterns overlap to a sum to form an exposure intensity distribution of the photosensitive layer.

5. The method of claim 4, wherein the overlapping occurs by unclear imaging of the micromirror in the exposure pattern.

6. The method of claim 4, wherein pixels of the at least two exposure patterns are exposed such that the at least two exposure patterns are sequentially illuminated one after the other, and the at least two exposure patterns are displaced to have a relative displacement between respective ones of the micromirror devices and the photosensitive layer that is less than one pixel width.

7. The method of claim 1, wherein exposure pattern grid lines of the exposure pattern are horizontal and/or vertical, and wherein the exposure pattern grid lines are configured to extend obliquely and/or be distorted.

8. The method of claim 7, wherein the exposure pattern grid lines of the exposure pattern are horizontal so as to extend parallel to each other, and wherein the exposure pattern grid lines are configured to extend obliquely and/or be distorted.

9. The method of claim 8, wherein the exposure pattern grid lines are affine configured.

10. The method of claim 7, wherein the exposure pattern grid lines of the exposure pattern are perpendicular so as to extend parallel to each other, and wherein the exposure pattern grid lines are configured to extend obliquely and/or be distorted.

11. The method of claim 10, wherein the exposure pattern grid lines are affine configured.

12. The method of claim 1, wherein when the mirror intensity distribution further has regions respectively corresponding to regions surrounding pixels of the exposure pattern, the exposed pixels overlap in a time-delayed manner due to overlapping of adjacent mirror intensity distributions of the mirror intensity distribution.

13. An apparatus for exposing a photosensitive layer of a substrate, the apparatus comprising:

A substrate holder on which the substrate is fixed, the substrate holder being configured to move the substrate in a first direction; and

An optical system, the optical system comprising:

One or more micromirror devices configured to move in the first direction and in the second direction, the one or more micromirror devices each comprising a plurality of micromirrors each having a mirror intensity distribution with: the regions respectively correspond to pixels of an exposure pattern to be exposed on a partial region of the photosensitive layer; and

One or more light sources respectively configured to emit one or more light rays for reflection by the micromirrors during simultaneous and synchronous movement of the substrate and the one or more micromirror devices in the first direction to expose pixels of the exposure pattern respectively according to regions of the mirror intensity distribution respectively corresponding to the pixels of the exposure pattern,

Wherein the one or more micromirror devices and the substrate holder are respectively moved in the first direction simultaneously and synchronously at least during the respective exposure of the pixels of the exposure pattern, and

Wherein the one or more micromirror devices are moved in the second direction opposite to or perpendicular to the first direction after exposing the pixels of the exposure pattern, respectively, wherein when the second direction is perpendicular to the first direction, the displacement of the one or more micromirror devices occurs in a step less than an imaging width of an individual pixel,

Wherein a measurement optic is integrated in the optical system, coupling the one or more light rays using a beam splitter of the measurement optic, wherein adjacent mirror intensity distributions of the plurality of micromirrors overlap as a sum of the mirror intensity distributions of each illuminated pixel of the exposure pattern to give a pattern intensity distribution of the exposure pattern, wherein the beam splitter couples light deflected by the layer to be exposed out of an optical path carried on the one or more micromirror devices for exposure.

14. The apparatus of claim 13, wherein when the mirror intensity distribution further has regions respectively corresponding to regions surrounding pixels of the exposure pattern, the exposed pixels overlap in a time-delayed manner due to overlapping of adjacent mirror intensity distributions of the mirror intensity distribution.